In any other week, today would be a landmark for immigration reform -- but as more information emerges about the suspects tied to the Boston Marathon bombings, momentum for action on immigration seems to have taken a hit.

At least one senator suggested that attacks by foreign-born suspects should put the brakes on Washington's current push for immigration reform.

"Given the events of this week, it's important for us to understand the gaps and loopholes in our immigration system," Sen. Chuck Grassley, R-Iowa, said at a hearing on immigration reform today. "While we don't yet know the immigration status of people who have terrorized the communities in Massachusetts, when we find out it will help shed light on the weaknesses of our system. How can individuals evade authority and plan such attacks on our soil?

"How can we beef up security checks on people who wish to enter the United States?" Grassley asked. "How do we ensure that people who wish to do us harm are not eligible for benefits under the immigration laws, including this new bill before us?"

Conservative commentator Ann Coulter cited the Boston suspects in a jab at Sen. Marco Rubio, R-Fla., whom she has criticized for advocating for changes to immigration law as a member of the so-called "Gang of Eight" that negotiated a current immigration reform plan before Congress.

Asked about Boston and immigration, Rubio's spokesman, Alex Conant, said, "There are legitimate policy questions to ask and answer about what role our immigration system played, if any, in what happened. Regardless of the circumstances in Boston, immigration reform that strengthens our borders and gives us a better accounting of who is in our country and why will improve our national security."

"Americans will reject any attempt to tie the terrorists responsible for the attacks in Boston with the millions of decent, law-abiding immigrants currently living in the U.S, and those hoping to immigrate here in the future," Conant said.

Suspects in the Boston attack, Dzhokhar Tsarnev, 19, for whom authorities are still searching, and Tamerlan Tsarnaev, 26, who was killed in a shootout early this morning, have been identified as ethnically Chechen. Both were born in Kyrgyzstan.

Dzhokhar Tsarnev became a U.S. citizen on Sept. 11, 2012, ABC News has learned.

Friday marked the beginning of the first full Senate Judiciary Committee hearing on immigration reform.

This week, the Gang of Eight unveiled a proposal, including added border-security requirements and new citizenship eligibility for immigrants who entered the country illegally. The much-anticipated bill is expected to serve as a starting point for discussion of further changes to U.S. immigration laws.

Unlike Grassley, others speaking at the hearing argued that the new immigration measures would allow for stronger, not weaker, tracking and security.

"I'd like to ask that all of us not jump to conclusions regarding the events in Boston or try to conflate those events with this legislation," Sen. Chuck Schumer, D-N.Y., a Gang of Eight member, said at the same hearing. "In general, we're a safer country when law enforcement knows who is here, has their fingerprints, photos, etc., has conducted background checks and no longer needs to look at needles through haystacks.

"Two days ago, as you may recall, there were widespread erroneous reports of arrests being made," Schumer said. "This just emphasizes how important it is to allow the actual facts to come out before jumping to any conclusions about Boston."

Sens. John McCain, R-Ariz., and Lindsey Graham, R-S.C., also members of the Gang of Eight, said the Boston attacks were a reason to move ahead with immigration reform, not to delay it.

"In the wake of this week's terrorist attack in Boston, some have already suggested that the circumstances of this terrible tragedy are justification for delaying or stopping entirely the effort for comprehensive immigration reform. In fact the opposite is true," McCain and Graham said in a written statement. "Immigration reform will strengthen our nation's security by helping us identify exactly who has entered our country and who has left -- a basic function of government that our broken immigration system is incapable of accomplishing today."

"It's the right question at the right time, because we're talking about what to do with foreigners in the United States or coming to the United States. And it's put in the context, clearly, of our national security first," Gang of Eight member Sen. Dick Durbin, D-Ill., said in an interview set to air tonight on Bloomberg TV's "Political Captial With Al Hunt."

Former White House press aide Tony Fratto, who worked under President George W. Bush, warned on Twitter against drawing any comparisons.

"There is no lesson or consequence from events in #Boston relevant to the immigration reform debate. Stop that idiocy," Fratto tweeted.